Oiling systems for internal combustion engines



March 29, 1955, H. E. BRUNS 2,705,056

OIYLING SYSTEMS FOR INTERNAL COMBUSTION ENGINES Filed Jan. 22.- 1953 2 Sheets-Sheet l INVENTOR.

March 29, 1955 H. E. BRUNS OILING SYSTEMS FOR INTERNAL COMBUSTION ENGINES 2 SheetsSheet 2 Filed Jan. 22. 1953 United States Patent OILING SYSTEMS FOR INTERNAL COMBUSTION ENGINES Harold E. Bruns, New Holstein, Wis., assignor to Hart- Carter Company, Peoria, Ill., a corporation of Delaware Application January 22, 1953, Serial No. 332,614

12 Claims. (Cl. 184-6) This invention relates to improvements in oiling systems for internal combustion engines.

In the use of internal combustion engines it is often necessary to have an auxiliary power take-off which is in a plane at right angles to the plane of the main drive shaft from the engine. This requirement is present in power lawn mowers of the type in which the blade is rotatable in a horizontal plane, when it is desired to render such lawn mower self-propelled.

In copending application of Alfred S. Bosma, Serial No. 296,879, filed July 2, 1952, an internal combustion engine is disclosed having an auxiliary drive of the general type contemplated by the present invention. In the structure of this copending application the oil pump had to be mounted above the crankcase, and oil had to be sucked up through a tube to the pump. Pumps for this prior type of construction had to be manufactured with great precision in order to operate properly, and a haphazard splashing of oil from the crankshaft or other parts had to be relied upon to lubricate the mechanism for the auxiliary drive.

It is a general object of the present invention to provide an improved internal combustion engine of the class described having an improved lubrication system which is reliable and which provides positive pressurized lubrication for all parts, including the worm, wormwheel, and bearings for the auxiliary drive, when an auxiliary drive is employed.

A further object of the invention is to provide an improved internal combustion engine wherein the oil pump is part of the auxiliary drive unit, is carried by the end plate on which the auxiliary drive is mounted, and is driven by the same gear train which operates the auxiliary drive.

A more specific object of the invention is to provide an improved internal combustion engine of the class described in which the oil pump is at all times primed by reason of its being positioned in the oil sump below the level of the oil therein, whereby a pump can be used which has been manufactured with less precision than is required for pumps which are located above the level of the oil.

A further object of the invention is to provide an improved internal combustion engine of the class described in which the pump is part of a separable unit which is readily removable from the engine. This simplifies the manufacture and repair of the pump and permits testing of the pump apart from the engine proper.

With the above and other objects in view, the invention consists of the improved internal combustion engine, and all of its parts and combinations as set forth in the claims, and all equivalents thereof.

In the drawings accompanying and forming a part of this specification, wherein one complete embodiment of the preferred form of the invention is shown, and wherein like characters of reference indicate the same parts in all of the views:

Fig. 1 is a perspective view showing the improved engine as used in a self-propelled power lawn mower of the type having a horizontally rotatable blade, part of the mower being omitted;

Fig. 2 is a generally horizontal sectional view taken through the improved engine approximately along the line 22 of Fig. 3; and

Fig. 3 is a vertical sectional view through the main portion of the engine, the upper portion of the engine being removed.

2,705,056 Patented Mar. 29, 1955 Referring more particularly to the drawings, the internal combustion engine is designated generally by the numeral 5 and includes a cylinder 6 having a piston 7 (Figs. 2 and 3) movable therein. A connecting rod 8 links the piston 7 to the crank 9 of a vertical crankshaft 10.

The lower portion of the engine crankcase is enlarged as at 11 to form an oil sump, the bottom of the portion 11 having an upstanding bored boss 12 through which the lower end of the crankshaft projects. When the engine is used for driving a power lawn mower of the type shown in Fig. l, the horizontal blade 50 may be connected directly to the lower end of the shaft 10, below the portion of the lawn mower (not shown) which forms a cover for said blade and which supports the engine.

The end of the crankcase which is opposite the piston 6 has an opening for substantially its full height, the latter including the height of the portion 11. This end of the crankcase is closed by an end plate or cover 13 removably held in place by bolts 14 (Fig. 1).

The cover 13 has a hollow, outwardly projecting portion 15 with coaxial bearing bosses 16 and 17 projecting horizontally from opposite sides thereof. An auxiliary drive shaft 18 is journaled in the bearing bosses 16 and 17 and has ends projecting laterally from the engine as shown in Figs. 1 and 2. Mounted loosely on the auxiliary drive shaft 18 within the hollow cover portion 15 is a wormwheel 19. Pinned to the shaft 18 within the hollow cover portion 15 is a clutch sleeve 20 to which one end of a clutch spring 21 is connected. The other end of the spring 21 embraces a hub 22 on the wormwheel 19. A clutch controlling member 23, when actuated, causes wrapping of the spring 21 around the hub 22, so that the wormwheel 19 is thereby connected to the auxiliary drive shaft 18. This type of wrap-around clutch is well known in the art, and its structure is therefore not described in detail.

Referring to Fig. 3, the cover plate 13 is formed with vertically spaced inwardly projecting horizontal flanges 24 and 25 which have alined, vertical bores 26 and 27 provided with flanged bearing sleeves 28 and 29. A vertical shaft 30 having an axial bore 31 is journaled in the bearing sleeves 28 and 29. Keyed to the shaft 30 between the bearing sleeves is a worm 32 having elongated hub portions 33 and 34. A gear 35, which is fixed on the hub portion 34, meshes with a gear 36 fixed to the crankshaft 10 at the upper end of the boss 12.

The upper end of axial bore 31 is closed by a plug 37, there being a diametrical bore 38 in the shaft 30 which registers with a port 39 in hub portion 33 as shown. The portion of the shaft 30 which is within the sleeve 28 is provided with a port 48 extending radially therethrough and communicating with the axial bore 31. The axial bore 31 terminates within the bearing shell 29, and the shaft 30 has a circumferential oil groove 40 within said bearing shell, there being a port 41 affording communication between the oil groove 40 and the axial bore 31. The bearing sleeve 29 has a port 42 which registers with the oil groove 40, and the flange 25 is formed with an L-shaped passage 43 which affords communication between the port 42 and the underside of said flange.

The shaft 30 projects below the flange 25 and is drivingly connected to a gear type oil pump 44 having a casing 45 fixed to the underside of the flange 25. The pump 44 has an inlet 46 located within an enclosing screen 47 at the bottom of the oil sump ll of the crank case, said pump and its inlet being positioned below the level of the oil in the portion 11. The outlet of the pump 45 communicates with the passage 43 in flange 25.

During operation of the improved engine the oil pump 44 is driven by gears 36 and and shaft 30, and oil is pumped under pressure through the passage 43, port 42, groove 40, and port 41 into the axial bore 31. Oil in the groove effectively lubricates the bearing shell 29, and oil under pressure flowing to the upper bearing shell 28 through the port 48, effectively lubr'icates the latter. Oil under pressure flows through the diametrical bore 38 and port 39, squirting from the latter as the shaft 30 and worm 32 rotate, thereby spraying lubricating oil on the working parts of the engine which are located in the crankcase and on the parts of the auxiliary drive which require lubrication.

Since the oil pump 45 is located below the oil level in the sump, said pump is continually primed. Thus the pump 45 need not be manufactured with the same precision that is required for oil pumps located out of the sump.

The entire auxiliary drive unit and oil pumping system can be removed from the engine by simply unbolting the plate 13 from the engine crankcase. This construction greatly simplifies the manufacture and repair of the improved engine. During manufacture, the auxiliary drive unit and pump can be tested apart from the engine and before it is assembled thereon. While the incorporation of a lubricating system into an auxiliary drive unit carried by plate 13 is particularly advantageous, it is obvious that an oil pump which is arranged on a removable end plate so as to be positioned in an oil sump and driven by the gears and 36 when the end plate is in place. is novel and advantageous regardless of Whether the end plate also carries an auxiliary drive.

Various other changes and modifications may be made without departing from the spirit of the invention, and all of such changes are contemplated as may come within the scope of the claims.

What I claim is:

1. In an internal combustion engine having a crankshaft, a gear fixed on said crankshaft, a crankcase formed with an opening, a removable cover closing said opening. an oil pump connected to the inner side of said cover. a tubular drive shaft for said pump rotatably mounted on said cover and extending along the inner side thereof close to said cover and within said crankcase and through which said pump discharges oil, said drive shaft having a discharge port positioned to direct oil onto said crankshaft as the drive shaft is rotated. and a gear fixed to said oil pump drive shaft and meshing with said crankshaft gear, said gears being disengageable upon removal of said cover plate from said crankcase said pump and its drive shaft having a combined length length less than the corresponding dimension of the crankcase opening so that they are Withdrawable as a unit with the cover through the opening by movement in a direction transversely of the longitudinal axis of the pump drive shaft when the cover is removed.

2. In an internal combustion engine having a crankcase formed with an opening and having a crankshaft, a cover closing said crankcase opening; an oil pump connected to the inner side of said cover, a tubular drive shaft for said pump rotatably mounted on said cover within said crankcase and through which said pump discharges oil, said drive shaft having a discharge port positioned to direct oil onto said crankshaft as the drive shaft is rotated; means for transmitting power from said crankshaft to said drive shaft; an auxiliary drive shaft rotatably carried by said cover and having a portion located in said crankcase; and means for transmitting power from said pump drive shaft to said auxiliary drive shaft.

3. In an internal combustion engine having a crankcase formed with an opening and having a crankshaft; a removable cover closing said crankcase opening; an oil pump connected to the inner side of said cover; a tubular drive shaft for said pump rotatably mounted on said cover within said crankcase and through which said pump discharges oil; means for transmitting power from said crankshaft to said pump drive shaft; an auxiliary drive shaft rotatably carried by said cover and having a portion positioned in said crankcase; a gear fixed to said pump drive shaft; and a gear fixed on said auxiliary drive shaft within the crankcase and meshing with said first gear to form a driving connection for said auxiliary drive shaft. said oil pump shaft having a discharge port positioned to direct oil onto said crankshaft and onto said gears for the auxiliary drive as the pump drive shaft is rotated.

4. In an internal combustion engine having a crankcase formed with an opening and having a crankshaft. said crankcase having an oil sump, a removable cover closing said crankcase opening; an oil pump connected to the inner side of said cover to be located in the oil in said sump when the cover is in place, a tubular drive shaft for said pump rotatably mounted on said cover within said crankcase and through which said pump discharges oil from the sump; means for transmitting power from said crankshaft to said pump drive shaft; an auxiliary drive shaft rotatably carried by said cover and having a portion positioned in said crankcase; a gear fixed to said pump drive shaft; and a gear fixed on said auxiliary drive shaft within the crankcase and meshing with said first gear to form a driving connection for said auxiliary drive shaft, said oil pump shaft having a discharge port positioned to direct oil onto said crankshaft and onto said gears for the auxiliary drive as the pump drive shaft is rotated.

5. In an internal combustion engine having a crankcase formed with an opening and having a crankshaft; a cover closing said crankcase opening; an oil pump connected to the inner side of said cover; a tubular drive shaft for said pump rotatably mounted on said cover within said crankcase and through which said pump discharges oil; an auxiliary drive shaft rotatably carried by said cover and having a portion positioned in said crankcase; a first gear fixed on said pump drive shaft; a second gear fixed on said auxiliary drive shaft within the crankcase and meshing with said first gear to form a driving connection for said auxiliary drive shaft, said oil pump shaft having a discharge port positioned to direct oil onto said crankshaft and onto said first and second gears as the pump drive shaft is rotated; and means for transmitting power from said crankshaft to said pump drive shaft, said means including normally engaged transmission parts on said crankshaft and cover positioned for disengagement upon removal of said cover from said crankcase opening.

6. In an internal combustion engine having a crankcase formed with an opening and having a crankshaft; a cover closing said crankcase opening; an oil pump connected to the inner side of said cover; a tubular drive shaft for said pump rotatably mounted on said cover within said crankcase and through which said pump discharges oil; an auxiliary drive shaft rotatably carried by said cover and having a portion positioned in said crankcase; a first gear fixed on said pump drive shaft; a second gear fixed on said auxiliary drive shaft within the crankcase and meshing with said first gear to form a driving connection for said auxiliary drive shaft; a third gear fixed on said crankshaft within said crankcase; and a fourth gear fixed on said oil pump drive shaft and meshing with said third gear to form a driving connection for said pump, said third and fourth gears being positioned for disengagement upon removal of said cover from said crankcase opening, and said oil pump shaft having a discharge port positioned to direct oil onto said crankshaft and onto said gears as the pump drive shaft is rotated.

7. In an internal combustion engine having a crankcase formed with an opening and having a crankshaft, a cover closing said crankcase opening, an oil pump connected to the inner side of said cover and having a drive shaft, means for transmitting power from said crankshaft to said pump drive shaft, an auxiliary drive shaft rotatably carried by said cover and having a portion located in said crankcase, and means for transmitting power from said pump drive shaft to said auxiliary drive shaft.

8. In an internal combustion engine having a crankcase formed with an opening and having a crankshaft, a removable cover closing said crankcase opening, an oil pump connected to the inner side of said cover and having a drive shaft, means for transmitting power from said crankshaft to said pump drive shaft, an auxiliary drive shaft rotatably carried by said cover and having a portion located in said crankcase, and means for transmitting power from said pump drive shaft to said auxiliary drive shaft, said oil pump and auxiliary drive shaft being removable as a unit with said cover.

9. In an internal combustion engine having a crankcase formed with an opening and having a crankshaft, a removable cover closing said crankcase opening, an oil pump connected to the inner side of said cover and having a drive shaft, means for transmitting power from said crankshaft to said pump drive shaft, an auxiliary drive shaft rotatably carried by said cover and having a portion located in said crankcase, a gear fixed to said pump drive shaft, and a gear fixed to said auxiliary drive shaft within the casing and meshing with said first gear to form a driving connection for said auxiliary drive shaft, said pump, auxiliary drive shaft and said gears being removable as a unit with the cover.

10. In an internal combustion engine having a crank case formed with an opening and having a crankshaft, said crankcase having an oil sump, a removable cover closing said crankcase opening, an oil pump connected to the inner side of said cover to be located in the oil in said sump when the cover is in place, a drive shaft for said pump rotatably mounted on the inside of said cover within said crankcase, means for transmitting power from said crankshaft to said pump drive shaft, an auxiliary drive shaft rotatably carried by said cover and hav ing a portion positioned in said crankcase, a gear fixed to said pump drive shaft, and a gear fixed to said auxiliary drive shaft within the crankcase and meshing with said first gear to form a driving connection for said auxiliary drive shaft.

11. In an internal combustion engine having a crankcase formed with an opening and having a crankshaft, a removable cover closing said crankcase opening, an oil pump connected to the inner side of said cover and having a drive shaft, an auxiliary drive shaft rotatably carried by said cover and having a portion located in said crankcase, and means for transmitting power from said crankshaft to said pump drive shaft, said means including normally engaged transmission parts on said crankshaft and cover positioned for disengagement upon removal of said cover from said crankcase opening, and means for transmitting power from said pump drive shaft to said auxiliary drive shaft, said oil pump and auxiliary drive shaft being removable as a unit with said cover.

12. In an internal combustion engine having a crankcase formed with an opening and having a crankshaft, a removable cover closing said crankcase opening, an oil pump connected to the inner side of said cover and having a drive shaft, an auxiliary drive shaft rotatably carried by said cover and having a portion located in said crankcase, a first gear fixed to said pump drive shaft, a second gear fixed on said auxiliary drive shaft within the crankcase and meshing with said first gear to form a driving connection for said auxiliary drive shaft, a third gear fixed on said crankshaft within said crankcase, and a fourth gear fixed on said oil pump drive shaft and meshing with said third gear to form a driving connection for said pump, said third and fourth gears being positioned for disengagement upon removal of said cover from said crankcase opening, and said first, second and fourth gears, together with said pump and auxiliary drive shaft being removable as a unit with said cover.

References Cited in the file of this patent UNITED STATES PATENTS 1,288,302 Vincent Dec. 17, 1918 1,565,872 Trautner Dec. 15, 1925 FOREIGN PATENTS 158,648 Great Britain Feb. 7, 1921 

